Recently, for improved functionality, portable wireless devices provided with a communicating means built into a body thereof, for communication by means of RFID (Radio Frequency Identification), which is a contactless IC (Integrated Circuit) chip, and the like, are becoming common (for example, see Patent Document 1).
In addition, as shown in Patent Document 1, although portable wireless devices are generally provided with a retractable main antenna outside a body thereof, for communicating with a mobile communication network, portable wireless devices with a main antenna built into a body thereof, for a more sophisticated design, are becoming common recently.    Patent Document 1: Japanese Unexamined Patent Application, First Publication No. 2004-227046